Accelerator Position Detection Device Neutral State
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Solution Overview
Problem
Existing accelerator position detection devices struggle to accurately detect the neutral state of a handlebar grip that can be turned in both positive and negative directions from a neutral position, leading to issues with precise neutral position determination and increased failure detection dispersion.
Innovation Solution
The device incorporates a handlebar grip that can be turned in both directions with energization to a neutral position, featuring two accelerator position sensors with distinct voltage output characteristics, allowing for differential detection of angles and failure judgment, and a controller for executing control based on these outputs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the handlebar grip is made turnable in both positive and negative directions from neutral position, then operational versatility is improved, but neutral position detection accuracy deteriorates due to dispersion
Solution Approach 1:
The detection range is segmented into two distinct regions: a first detection region for positive rotation angles and a second detection region for negative rotation angles. Each region has its own dedicated sensor, which eliminates the confusion of determining which sensor's output to use when the handlebar is in either direction from neutral, thereby improving neutral position detection accuracy while maintaining bidirectional rotation capability.
2Adaptability or versatility
If separate control operations for positive and negative direction turning are implemented, then control functionality is improved, but device complexity increases due to additional stopper and energizing member structures
Solution Approach 1:
The patent replaces the mechanical stopper and energizing member structure with an electronic detection system using two accelerometers. The first accelerometer detects positive rotation angles and the second detects negative rotation angles, allowing separate control operations to be implemented through software logic rather than additional mechanical components, thus reducing device complexity while maintaining functionality.
3Reliability
If two accelerator position sensors are used for failure detection, then reliability is improved, but ECU operation load increases due to correction processing requirements
Solution Approach 1:
Each accelerometer is assigned to detect a specific local range: the first accelerometer is configured to detect only positive rotation angles, and the second accelerometer is configured to detect only negative rotation angles. This local specialization allows the ECU to simply compare which sensor is active and verify its output against expected ranges, eliminating the need for complex correction processing and reducing computational load while maintaining failure detection capability.
4Reliability
If sensor output magnitude relation is used for failure detection in crossing areas, then failure detection capability is improved, but detection precision deteriorates due to output value errors
Solution Approach 1:
The patent segments the detection ranges of the two sensors so that the first sensor detects positive angles and the second sensor detects negative angles. This segmentation eliminates the crossing area problem where magnitude relation comparison becomes unreliable due to output value errors. By ensuring each sensor operates in its dedicated range without overlap, failure detection precision is improved while maintaining the ability to detect sensor failures.
Data Source
AI summary
An accelerator position detection device includes a handlebar grip that is turnable in a normal rotation direction and in a reverse rotation direction from a neutral position and is energized to the neutral position when no operation is applied; accelerator position sensors that output voltage according to an angle of the handlebar grip and that include a first sensor and a second sensor; and a detector that detects an angle for control for controlling a vehicle on the basis of the angle of the handlebar grip according to output from the accelerator position sensors. The detector detects an angle as a positive value on the basis of a first voltage when the first voltage in a rising range is output, and the detector detects an angle as a negative value on the basis of a second voltage when a first initial value not located in the rising range is output.